[R] Missing information in source()

Duncan Murdoch murdoch.duncan at gmail.com
Tue Nov 7 21:33:29 CET 2017

On 07/11/2017 3:01 PM, Tom Backer Johnsen wrote:
> Dear R-help,
> I am running a Mac under Sierra, with R version 3.4.2 and RStudio 1.1.383.  When running head () or tail () on an object in a script using source (<script name>) nothing appears in the output file, but if I use these commands in the normal R window the normal output appears.
> What am I doing wrong?

You aren't printing the results.  source() has an argument "print.eval" 
which defaults to FALSE; you can change it.  A common way to do that is 
to set echo=TRUE, but echoing the input is not necessary.

So use

source(filename, echo = TRUE)

for a lot of output, or

source(filename, print.eval = TRUE)

for somewhat less.

In most cases an explicit print() will be needed if the head() or tail() 
is in a loop or in a function.

Duncan Murdoch

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